Business Unit Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 item	Sep. 30, 2013
Business Unit Segment Information
Number of operating segments			4
Revenues:
Lease contracts	$ 129,004	$ 122,771	$ 370,597	$ 367,088
Management contracts	77,878	77,681	252,764	256,435
Total parking services revenue	206,882	200,452	623,361	623,523
Reimbursed management contract revenue	173,405	154,858	507,122	472,737
Total revenue	380,287	355,310	1,130,483	1,096,260
Gross profit
Lease contracts	12,484	7,075	30,014	27,260
Management contracts	31,137	33,001	96,793	99,185
Total gross profit	43,621	40,076	126,807	126,445
Gross Margin
General and administrative expenses	24,123	20,494	75,185	75,310
General and administrative expense percentage of gross profit	55.00%	51.00%	59.00%	63.00%
Depreciation and amortization	7,630	7,959	22,523	23,704
Operating income	11,868	11,623	29,099	27,431
Other expenses (income):
Interest expense	4,162	4,818	13,782	14,421
Interest income	(144)	(108)	(336)	(347)
Total other expenses (income)	4,018	4,710	13,446	14,074
Income before income taxes	7,850	6,913	15,653	13,357
Income tax (benefit)	2,763	2,448	(421)	4,359
Net income	5,087	4,465	16,074	8,998
Less: Net income attributable to noncontrolling interest	785	721	2,162	2,070
Net income attributable to SP Plus Corporation	4,302	3,744	13,912	6,928
Region One
Other expenses (income):
Net gain related to sale of rights associated with certain contracts				2,700
Operating segment \| Region One
Revenues:
Lease contracts	79,675	77,970	227,490	230,444
Management contracts	23,058	23,733	73,647	80,473
Total parking services revenue	102,733	101,703	301,137	310,917
Gross profit
Lease contracts	5,232	3,649	10,209	12,640
Management contracts	11,351	12,045	34,204	36,082
Total gross profit	16,583	15,694	44,413	48,722
Gross Margin
Lease contracts (as a percent)	7.00%	5.00%	4.00%	5.00%
Management contracts (as a percent)	49.00%	51.00%	46.00%	45.00%
Operating segment \| Region Two
Revenues:
Lease contracts	1,094	1,065	3,550	3,396
Management contracts	4,845	8,467	20,870	24,344
Total parking services revenue	5,939	9,532	24,420	27,740
Gross profit
Lease contracts	96	17	237	388
Management contracts	2,675	3,572	8,981	7,215
Total gross profit	2,771	3,589	9,218	7,603
Gross Margin
Lease contracts (as a percent)	9.00%	2.00%	7.00%	11.00%
Management contracts (as a percent)	55.00%	42.00%	43.00%	30.00%
Operating segment \| Region Three
Revenues:
Lease contracts	12,840	11,791	36,760	34,930
Management contracts	13,292	13,738	42,485	46,321
Total parking services revenue	26,132	25,529	79,245	81,251
Gross profit
Lease contracts	1,687	1,402	3,938	3,578
Management contracts	5,876	4,947	16,504	17,706
Total gross profit	7,563	6,349	20,442	21,284
Gross Margin
Lease contracts (as a percent)	13.00%	12.00%	11.00%	10.00%
Management contracts (as a percent)	44.00%	36.00%	39.00%	38.00%
Operating segment \| Region Four
Revenues:
Lease contracts	12,716	10,602	35,299	33,075
Management contracts	23,141	22,988	78,150	73,815
Total parking services revenue	35,857	33,590	113,449	106,890
Gross profit
Lease contracts	1,062	842	2,627	2,693
Management contracts	6,162	4,749	19,868	17,495
Total gross profit	7,224	5,591	22,495	20,188
Gross Margin
Lease contracts (as a percent)	8.00%	8.00%	7.00%	8.00%
Management contracts (as a percent)	27.00%	21.00%	25.00%	24.00%
Operating segment \| Region Five
Revenues:
Lease contracts	22,787	22,086	67,929	68,229
Management contracts	10,715	8,849	30,823	30,261
Total parking services revenue	33,502	30,935	98,752	98,490
Gross profit
Lease contracts	4,639	3,867	14,280	12,778
Management contracts	5,078	4,200	14,305	12,247
Total gross profit	9,717	8,067	28,585	25,025
Gross Margin
Lease contracts (as a percent)	20.00%	18.00%	21.00%	19.00%
Management contracts (as a percent)	47.00%	47.00%	46.00%	40.00%
Operating segment \| Other
Revenues:
Lease contracts	(108)	(743)	(431)	(2,986)
Management contracts	2,827	(94)	6,789	1,221
Total parking services revenue	2,719	(837)	6,358	(1,765)
Gross profit
Lease contracts	(232)	(2,702)	(1,277)	(4,817)
Management contracts	(5)	3,488	2,931	8,440
Total gross profit	$ (237)	$ 786	$ 1,654	$ 3,623
Gross Margin
Lease contracts (as a percent)	215.00%	364.00%	296.00%	161.00%
Management contracts (as a percent)	0.00%	(3711.00%)	43.00%	691.00%

Represents the amount of net gain (loss) from sale of rights associated with certain contracts.

No definition available.

Name:	sp_GainLossOnSaleOfRights
Namespace Prefix:	sp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents general and administrative expenses expressed as a percentage of gross profit.

+ References

No definition available.

+ Details

Name:	sp_GeneralAndAdministrativeExpensesPercentageOfGrossProfit
Namespace Prefix:	sp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	sp_GrossProfitPercentageAbstract
Namespace Prefix:	sp_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents lease contracts gross profit expressed as a percentage of lease contracts revenue.

+ References

No definition available.

+ Details

Name:	sp_LeaseContractsGrossMarginPercentage
Namespace Prefix:	sp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Aggregate revenue from fees, whether long-term or daily, charged for parking facilities less cost of parking services, directly attributable to the revenue generation activity.

+ References

No definition available.

+ Details

Name:	sp_LeaseContractsGrossProfit
Namespace Prefix:	sp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Aggregate revenue from management contracts less cost of parking services, directly attributable to the revenue generation activity.

+ References

No definition available.

+ Details

Name:	sp_ManagementContractsGrossProfit
Namespace Prefix:	sp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents management contracts gross profit expressed as a percentage of management contracts revenue.

+ References

No definition available.

+ Details

Name:	sp_ManagementContractsGrossProfitPercentage
Namespace Prefix:	sp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Aggregate revenue during the period from parking services rendered in the normal course of business.

+ References

No definition available.

+ Details

Name:	sp_ParkingServicesRevenueNet
Namespace Prefix:	sp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The current period expense charged against earnings on long-lived, physical assets not used in production, and which are not intended for resale, to allocate or recognize the cost of such assets over their useful lives; or to record the reduction in book value of an intangible asset over the benefit period of such asset; or to reflect consumption during the period of an asset that is not used in production.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

+ Details

Name:	us-gaap_DepreciationAndAmortization
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The aggregate total of expenses of managing and administering the affairs of an entity, including affiliates of the reporting entity, which are not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

+ References

+ Details

Name:	us-gaap_GeneralAndAdministrativeExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.

+ References

+ Details

Name:	us-gaap_GrossProfit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_GrossProfitAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Sum of operating profit and nonoperating income or expense before Income or Loss from equity method investments, income taxes, extraordinary items, and noncontrolling interest.

+ References

+ Details

Name:	us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(h))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph h

-Article 4

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Income Tax Expense (or Benefit)

-URI http://asc.fasb.org/extlink&oid=6515339

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 9

-Subparagraph (a),(b)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32639-109319

+ Details

Name:	us-gaap_IncomeTaxExpenseBenefit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of the cost of borrowed funds accounted for as interest expense.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-04.9)

-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 9

-Article 9

+ Details

Name:	us-gaap_InterestExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_InterestIncomeExpenseNetAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Revenue, comprised of base and incentive revenue derived from the management of joint ventures, managing third-party properties, or another entity's operations.

+ References

+ Details

Name:	us-gaap_ManagementFeesRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of Net Income (Loss) attributable to noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 1A

-URI http://asc.fasb.org/extlink&oid=18733093&loc=SL4573702-111684

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 55

-Paragraph 4J

-URI http://asc.fasb.org/extlink&oid=35736750&loc=SL4591551-111686

+ Details

Name:	us-gaap_NetIncomeLossAttributableToNoncontrollingInterest
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 260

-SubTopic 10

-Section 45

-Paragraph 11

-URI http://asc.fasb.org/extlink&oid=7655603&loc=d3e1377-109256

+ Details

Name:	us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The aggregate amount of income or expense from ancillary business-related activities (that is to say, excluding major activities considered part of the normal operations of the business).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.7)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 7

-Article 5

+ Details

Name:	us-gaap_NonoperatingIncomeExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfOperatingSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The net result for the period of deducting operating expenses from operating revenues.

+ References

No definition available.

+ Details

Name:	us-gaap_OperatingIncomeLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The aggregate amount of other income amounts, the components of which are not separately disclosed on the income statement, resulting from ancillary business-related activities (that is, excluding major activities considered part of the normal operations of the business) also known as other nonoperating income recognized for the period. Such amounts may include: (a) dividends, (b) interest on securities, (c) profits on securities (net of losses), and (d) miscellaneous other income items.

+ References

+ Details

Name:	us-gaap_OtherNonoperatingIncome
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Revenue from fees, whether long-term or daily, charged for parking facilities.

+ References

+ Details

Name:	us-gaap_ParkingRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 55

-Paragraph 4K

-URI http://asc.fasb.org/extlink&oid=35736750&loc=SL4591552-111686

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 45

-Paragraph 19

-URI http://asc.fasb.org/extlink&oid=7656940&loc=SL4569616-111683

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 1A

-Subparagraph (a),(c)

-URI http://asc.fasb.org/extlink&oid=18733093&loc=SL4573702-111684

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 55

-Paragraph 4J

-URI http://asc.fasb.org/extlink&oid=35736750&loc=SL4591551-111686

+ Details

Name:	us-gaap_ProfitLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Repayment received or receivable for expenses incurred on behalf of a client or customer, other than those reimbursements received by landlords from tenants.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 605

-SubTopic 45

-Section 45

-Paragraph 23

-URI http://asc.fasb.org/extlink&oid=21915142&loc=d3e60722-111653

+ Details

Name:	us-gaap_ReimbursementRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Article 5

+ Details

Name:	us-gaap_SalesRevenueNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_SalesRevenueNetAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_SegmentReportingAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration